The Ultimate Guide To Companion Planting in Alberta [+Chart]

Companion planting has been practiced for many years.  There is no hard and fast scientific evidence for companion planting – it is more of an art based on the anecdotal notes of seasoned gardeners than on hard & fast scientific evidence.

And that can make vegetable companion planting confusing.

In this discussion about companion plants in the garden, we will:

  • Define companion planting
  • Talk about the benefits of companion planting
  • Share our vegetable companion planting chart with you

What is Companion Planting?

Companion planting is the practice of growing plants together or grouping them together side by side, like ‘companions’ or ‘buddies’, for the mutual benefit of each plant.

There are groups of vegetables and flowers that grow more robustly together than they do alone.  And conversely, there are certain plants that actually grow worse – their growth slows down or is impeded – by certain neighbouring plants.

Companion planting isn’t restricted to just growing vegetables, but companion planting herbs and flowers into the mix also works well.

In the world of companion plants, you will find that most information is uniform, but you may also run into some inconsistencies.  The reason for this is as we mentioned above – companion planting is highly based on information that has been collected over the years from gardening experience.

We would like to encourage you to stick with your gardening efforts and make your own notes about what works effectively for you.

Read on.

What Are The Benefits of Companion Planting?

The overarching benefit of companion planting is that plants grow better.

If you are already a gardener, you may be surprised to know that you are probably practicing companion planting but didn’t know it.

1. Plant Placement is Better

Because all vegetables, herbs, annuals, and perennials grow in varying heights and widths, how you place your plants in our garden is a part of companion planting.

2. Companion Planting Provides Optimal Sun Exposure

Not only do plants grow in different sizes, they all have their own preference for sun exposure.

For sun-loving plants, keep in mind to grow the shorter plants on the sunny side of your gardening space so that taller plants don’t shade out the smaller ones. Many vegetables and flowers will perform poorly if they don’t get enough sunshine.  The vegetables will be small, and flowering will be inconsistent.

For plants that prefer a break from the hot afternoon sun, plant them next to taller plants that will provide shelter at that time of day. Pansies and Hydrangeas appreciate taking shade from taller plants during the heat of the day.

3. Companion Planting Helps Control Bugs

Each type of plant gives off subtle odours. There are certain insects that are attracted to those smells and others are averse to those smells.

There is research that the delia antiqua fly that is the culprit for producing onion root maggots are attracted to the sulphur-based compounds in onions. That’s how they know they’re at the right plant.

If you smatter onions throughout the garden, it is thought that there isn’t a high concentration of the onion smell in one particular spot to attract them.

It seems that the flies get confused as to where to lay their eggs, resulting in less onion root maggots.

If you intersperse marigolds throughout a vegetable garden, they fight off nematodes in the ground and several flying insects like aphids and mosquitoes.

4. Companion Planting Provides Efficient Use of Space

Companion planting works well when gardening space is at a premium. With both raised bed gardening and square foot gardening, a good garden plan using companion planting will deploy that space effectively.

Check out the following blogs for more detailed discussion on implementing these techniques in your gardening space:

Square Foot Gardening

Raised Beds for Vegetable Gardening

5. Companion Planting Is Good For The Soil

Some plants take nutrients out of the soil, and other plants add nutrients to the soil.

For example, corn and tomatoes are both heavy feeding vegetables – they take a lot of nitrogen out of the soil. Legumes (or pulses) like peas and beans don’t feed heavily on nitrogen.  As a matter of fact, they add nitrogen to the soil.

This makes corn and beans great companions. And the soil stays balanced and healthy.

Related: Crop Rotation keeps soil healthy, too.  Read more about that in this blog.

Vegetable Companion Planting Chart

We have put together this Vegetable Companion Planting Chart to give you ideas as you plan your gardens; be they in ground, in raised beds, in square foot gardens, or in pots.  Remember that this is your garden, so you individualize it for what you need and what works best for you.

The column on the left has the main crop listed like beans, beets or carrots.

The column next to it is their lovers.  These are the plants that grow best next to the main crop.  You don’t have to plant all of them, just plant the ones that you’d like.

The third column is the haters.   Keep the main crop on the haters apart from one another.

The last column has additional notes of notable things to consider as you plan your garden.

To better help you understand our chart, here are also a few quick definitions:

  • Allium Family – onions, garlic, leeks, chives, shallots
  • Cole Crops – also known as cruciferous vegetables – includes broccoli, Brussels sprouts, cabbage, cauliflower, kale, kohlrabi, etc
  • Leaf crops – includes lettuce, lettuce mixes, spinach, Swiss chard
  • Root crops – the roots are the vegetables we eat – includes beets, carrots, potatoes, parsnips, onions, turnips
  • Squash family – includes squash, pumpkins, zucchini

Marigolds are included in this chart because of their overall benefit to gardens in general – they assist in controlling many garden pests and nematodes.

Happy growing!

– by Sharon Wallish Murphy



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About The Author

Sharon Wallish Murphy
Sharon grew up in the Wallish Greenhouse at the heels of her father, Charlie, who mentored her. Sharon’s passion is to share the love for growing and to empower others to find joy in their gardening journey, just like her dad.